Asbestos-containing pipe insulation takes many forms, including chalky mixtures of magnesia and asbestos, preformed fibrous asbestos wrapping, asbestos fiber felt, corrugated paper, and insulating cement. In most cases, the insulating material is covered with a protective jacket (lagging) made of cloth, tape, paper, metal or cement. Occasionally, asbestos millboard is used as outside lagging on removable insulating covers for stiffness. Lagging on pipes and boilers prevents spontaneous fiber release and helps protect against disturbance.
Exposure to airborne asbestos regardless of the level, involves some health risks. When damage occurs to asbestos insulation and lagging on pipes and valves, repair and/or removal of the material is essential. The potential for exposure to airborne asbestos during such operations cannot be ignored. Worker protection is essential and is, in general, demanded by law. Proper work area containment is highly recommended for all abatement techniques. Once abatement work begins, all uninvolved persons should be kept out of the area.
Containment typically means construction of barriers with 6 mil polyethylene plastic sheets joined with folded seams, and with sealing tape at the seams and boundaries. Air locks and worker decontamination facilities with showers are recommended. So, too, are reduced air pressure systems, such as disclosed in U.S. Pat. No. 4,604,111. Without adequate containment, increased exposure for building occupants is likely. Abatement activities should be conducted during vacations or other times when few people are in the building.
The cost of containment in such circumstances may equal or, indeed, exceed the cost of abatement. Further, it still requires that workers enter the containment area in order to conduct the abatement operation. Finally, it should be noted that the removal of the asbestos insulation from the pipes and valves still requires safe packaging of the material for removal from the containment area for ultimate disposition.
It is an object of this invention to provide a containment device which will be relatively inexpensive compared to general containment procedures of the past.
It is another object of this invention to provide a method of constructing a device suitable for asbestos and other hazardous material containment.
A further object of this invention is to provide a method for removing contaminates such as asbestos from pipes and valves in which the worker is protected and in which the cost of abatement is significantly reduced through reduced costs in containment and disposition of the final debris of the abatement procedure.
These and other objects will be apparent from the subsequent disclosure and appended claims.